A conventional customer-made pen generally includes a decorated barrel which includes a metal section 7 inserted into an outer section 6 as shown in FIGS. 9 and 10. The tolerance between the metal section 7 and the outer section 6 is so small that an assembling device 5 is needed to insert the metal section 7 into the outer section 6. The assembling device 5 includes a fixed frame 54 on one end of the base and a movable rod 52 movably extends through the fixed frame 54. An end part 53 is fixed to the distal end of the movable rod 52 and a recess is defined in the free end of the end part 53. A frame is fixed on the other end of the base and includes a link pivotably connected between a lever and a push rod. The outer section 6 is inserted into the recess in the end part 53 and the metal section 7 connected to the distal end of the push rod. By pivoting the lever, the push rod moves the metal section 7 toward the outer section 6 and forces the metal section 7 into the outer section 6. A block unit 51 includes multiple blocks 511, 512, 513 of different lengths and the blocks 511, 512, 513 are selectively mounted to the movable rod 52 and clamped between the fixed frame 54 and the end part 53 so as to set a fixed distance between the end part 53 and the distal end of the push rod. The distance is the length of the barrel.
However, the blocks 511, 512, 513 are easily lost because the assembling device lacks a proper storage place for the blocks 511, 512, 513. Once the blocks 511, 512, 513 are lost, the user has to unscrew the positioning bolts 541 which fix the movable rod 52 to the fixed frame 54, and then move the movable rod 52 to desired position and fix the movable rod 52 by the positioning bolts 541. This often requires several times of try to correctly set the movable rod 52 and increases the time required.
The present invention intends to provide a pen barrel assembling device which improves the shortcomings of the conventional pen barrel assembling device.